Light
presents substantial potential in disease treatment, where
the development of efficient photocatalysts could enhance the utilization
of photocatalytic systems in biomedicine. Here, we devised a novel
approach to designing and synthesizing photocatalysts of conjugated
polymers for photocatalytic CO2 reduction, relying on a
multiple linear regression model built with theoretically calculated
descriptors. We established a logarithmic relationship between molecular
structure and CO yield and identified the poly(fluorene-co-thiophene) deviant (PFT) as the optimal one. PFT excited a CO regeneration
ratio of 231 nmol h–1 in acetonitrile and 46 nmol
h–1 in an aqueous solution with a reaction selectivity
of 88%. Further advancements were made through the development of
liposomes encapsulating PFT for targeted macrophage delivery. By distributing
PFT on the liposome membranes, our constructed photocatalytic system
efficiently generated CO in situ from surrounding CO2.
This localized CO production served as an endogenous signaling molecule,
promoting the desirable polarization of macrophages from the M1 to
M2 phenotype. Consequently, the M2 cells reduced the secretion of
pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β). We
also demonstrated the efficacy of our system in treating lipopolysaccharide-induced
inflammation of cardiomyocytes under white light irradiation. Moreover,
our research provides a comprehensive understanding of the intricate
processes involved in CO2 reduction by a combination of
theoretical calculations and experimental techniques including transient
absorption, femtosecond ultrafast spectroscopy, and in situ infrared
spectroscopy. These findings pave the way for further advancements
of conjugated polymers and photocatalytic systems in biomedical investigation.